An understatement is an utterance that depicts something in a manner that gives it less importance, seriousness, makes it less bad, etc. than it actually is. In this example, the speaker makes use of such understatement to minimize the act of women eating children, who later would become mothers themselves.
Explanation: An understatement is made when less importance is given to a determined situation, in order for the reader be convinced that it's not so aggravating as the habit of eating children is being depicted in it. Also, the situation is even worse due to the fact that the women who were supposed to eat them would also become mothers, implying that their children would be eaten as well.
You will know when the introduction has moved on because at the end of the introduction, there is a thesis statement. The thesis statement is how you will know when the introduction has moved on.
